Einfluss der Grünlandnutzung auf die PPO-Aktivität in Rotklee

Summary

Several studies show that polyphenol oxidase (PPO) in red clover reduces proteolysis and increases nitrogen use efficiency of the ruminant, but not much is known about factors affecting PPO activity in red clover plants. PPO activity was analysed in red clover plants from legume-grass mixtures subjected to three different management systems. The cutting frequency (3 or 5 cuts) caused only minor differences in PPO activity, whereas a significant increase in PPO activity could be proved for the rota-tional grazing system (RG), compared to the simulated grazing system (SG, 5 cuts) with equal use frequency. Results indicate a metabolic adaptation of the red clover plants due to the grazing process itself, leading to a control factor which has to be considered in case of red clover nutrition properties.